The investigational protocols of the Pediatric Oncology Group (POG) form the foundation for the clinical and laboratory research programs in pediatric oncology at the University of Mississippi Medical Center (UMC) in Jackson, Mississippi. The cooperative research efforts of the POG member institutions are yielding important new information concerning the biology and therapy of most types of pediatric malignancies. The UMC and its POG affiliate institution, Keesler AFB Medical Center, are the only centers in Mississippi providing comprehensive care for children with cancer. The UMC's participation in the POG incorporates the multidisciplinary input of pediatric medical oncology, pediatric surgery, pediatric pathology, radiotherapy, radiology. cytogenetics, and immunology both locally and in the scientific and administrative activities of the group. The UMC principal investigator has recently served as POG New ALL (Acute Lymphocytic Leukemia) Committee chairman and is continuing to participate in all of the core and planning committee functions of the New ALL Committee. The POG protocols for children with newly diagnosed ALL include the classification protocols which explore the laboratory subclassification of ALL and route patients-to the specific treatment protocols for T, B, and non-T, non-B ALL. POG protocols specially designed for T-ALL and B-ALL, respectively, are improving the outcome of these poor risk groups of childhood ALL. The UMC is providing the current chair for the POG Cytogenetics Committee. The UMC is coordinating the POG 8035 (ALinC 13) and POG 8600 (ALinC 14) classification studies for patients with newly diagnosed ALL and will coordinate the POG 9000 (ALinC 15) classification study. The UMC is also coordinating the POG 8036 (ALinC 13) New ALL treatment study.